The teeth of the equine species continuously grow, and as such it is necessary to periodically file off overgrown surfaces and sharp projecting edges. The filing process is also known as rasping or "floating". Absent this periodic treatment, the animal's teeth will grow to a point where it can experience difficulty in chewing, or can develop tooth induced ulcerations of the soft mouth tissue and tongue. Devices to file a horse's teeth are well known in the art. They range from hand-held floats and rasps, to rasps mounted upon both reciprocating and rotary power tools. For example, U.S. Pat. No. 579,966 shows a veterinary file holder. Two lips or flanges are secured to a wire member, forming salient edges which overlap the edges of a file. U.S. Pat. No. 5,533,894 defines an equine dental float which includes a handle with a head at one end. The head has a trough-like structure with a plurality of individual teeth mounted in the trough. A pin mounted through an aperture in each of the plurality of teeth aligns the teeth and removably connects the teeth within the trough. Each tooth is polygon in shape and has a plurality of cutting edges, with one of the cutting edges of each tooth projecting upwardly out of the trough to form a filing surface. German Patent 26 37 915 depicts a tool for filing horse teeth having a reciprocating rasp in a U/rail supported by a rod connected to a drive housing. The joint between the rod and the housing is formed by a plate attached to the end of the rod and covering the housing interior and the drive mechanism. The tool can be handled more safely and allows rapid filing down of teeth without insertion of a lock in the horse's mouth. German Patent 30 02 386 comprises a teeth grinding instrument intended for the molars of horses having a motordriven grindstone. The grindstone is coupled by a chuck to a compressed air motor. The device also has one or more air outlet ports, together with a water pipe spraying onto the grinding area, and one or more fiber optic light sources. French Patent 1.052.653 describes 15 a rotary grinding device for animal dentistry. Mikita Model 4399D and 4399DW discloses a Cordless Equine Rasp. This device operates an 2,700 strokes per minute, has a 5/32 inch stroke, and weighs 5.3 lbs. Rotary motion provided by an electric is mechanically converted to reciprocating motion. The tool is marketed by the Mikita Corp. 3-11-8, Sumiyoshi-cho, Anjo, Aichi 446 Japan. EQUI-DENT Technologies, Inc., P.O. Box 5877, Sparks Nev. 89432-5877 (702) 358-6695, also markets an electrically powered reciprocating rasp for horses which operates at 1,200 oscillations per minute, has a 1 and 3/16 inch stroke, and weighs approximately 7.4 lbs. Mikita Model TR 3000V reciprocating saw forms the basis for the EQUI-DENT rasp.
None of the aforementioned prior art equine dentistry devices utilize compressed air to directly drive a rasp in a reciprocating fashion. Further, the aforementioned electricallydriven devices operate at no load speeds of no more than 2,700 oscillations per minute. When loaded down with the weight of a rasp and shaft, the speed of these devices is reduced substantially.